1. Field of the Invention
The present invention pertains to the art of aircraft and, more particularly, a folding wing assembly for an aircraft.
2. Description of the Prior Art
Folding wing assemblies for use on aircraft are known in the art as evidenced by U.S. Pat. Nos. 2,712,421, 3,039,721, 3,063,660, 3,081,053 and 4,717,093. In each of these prior art arrangements, a spanwise outboard wing section is pivotally attached to a spanwise inboard wing section for vertical pivotal movement about a longitudinal axis so as to be movable between folded and unfolded positions. A major problem associated with folding wing assemblies is to interconnect the inboard and outboard wing sections in such a manner as to maintain structural rigidity of the entire wing assembly while minimizing any aerodynamic drag created by the joint between the two wing sections. In order to assure structural rigidity, it is necessary to directly pivotally interconnect the interior structural supports of the wing sections instead of merely interconnecting the sections along their top surfaces, as described in the '721 patent mentioned above. In addition, in order to minimize aerodynamic drag, it is necessary that the surface above the joint area be flush with the upper surface of the wing sections when the wing assembly is in its unfolded position. In addition, it is necessary to assure that the joint area is sealed to prevent the passing air from entering this joint area and creating turbulence and increasing aerodynamic drag. The known prior art fails to achieve these important functions and therefore there is a need in the prior art for a folding wing assembly which is simple in construction yet structurally sound and which minimizes aerodynamic drag that can develop at the joint area between the inboard and outboard wing sections.